Abstract/Description

This study investigated pasting and sensory characteristics of Dioscorea?alata, an underutilized yam species, to ascertain its suitability for amala (a pasty yam product) in comparison with D.?rotundata. Pasting was determined by Rapid Visco-Analyser and the amala was prepared from parboiled and fermented yam flour. Using multiple comparison sensory test, the products were assessed on a 9-point scale by a 10-member trained panel. In RVU, the average pasting viscosities for test varieties were: peak 215.7, trough 198.7, breakdown 18.1, final 256.0 and setback 57.3 as against the reference with peak 322.6, trough 187.8, breakdown 134.8, final 359.3 and setback 171.5. Pasting viscosities were significantly (P?<?0.05) lower for test varieties; however, sensory results showed that D.?alata is equally good if not better for amala in terms of texture and color. The better suitability of D.?alata for amala could be attributed to parboiling of tubers and browning during drying.
Practical Applications
D.?alata has low economic value because it is less preferred for major yam products such as pounded yam, fufu, boiled or fried yam. However, the species has good potential for sustainable production and utilization, hence the need to diversify its food uses to enhance food security in producing areas. The results in this study have shown that D.?alata has relatively low pasting viscosities as compared to the most preferred species. However, its tubers are equally good for amala, a traditional delicacy in yam producing areas, which is usually made from the preferred species, in terms of textural and sensory properties. To enhance food security and add value to the species, its tubers could be processed to elubo, the flour for amala, which has the potential for longer storage and use during the hunger or off seasons of most tropical crops.